\0.. but that means "string end". left kinda undefined in JSON, so we occupy that empty space=)
I got interest in WAMP on abstract level a year ago when planning migration of application with about 5000 API methods... just got interested in pattern/prefix methods publishing. But when getting deeper (using "implement-to-learn" approach), started to feel its potential super-power for both big and small scopes.
This investigation resulted so far in java implementation of WAMP protocol itself and hybrid REST/WAMP router/client that enables dynamic REST end-point over WAMP router with generated client-oriented stub for API calls (that is something that was originally in mind when researching area of API gateways, but was never discovered).
So, there's multi-module maven project xLib (https://github.com/000ssg/xLib, mixture of my interests) that exposes implementation of WAMP protocol (without transport) - xLibWAMP, and "top-level" sample of its use: xLibWAMPHttpAPI_CS (actual demos in tests area).
While implementing, I noticed, the spec is continuously updated, so some doubts/questions got resolved with time. But still awaited specification for session detach/attach (as is mentioned in testament-related feature, but even not pre-drafted) and better procedure reflection (own design in use). And I had to introduce own feature (virtual session) to use same WAMP connection for multiple users (when translating REST calls to WAMP calls), that might be of some interest for this specification (as i guess).